Host age preference of Microplitis mediator (Hymenoptera: Braconidae), an endoparasitoid of Mythimna separata (Lepidoptera: Noctuidae)
Host age preference of Microplitis mediator (Hymenoptera: Braconidae), an endoparasitoid of Mythimna separata (Lepidoptera: Noctuidae)
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DOI：
10.1016/j.biocontrol.2006.09.002
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发表时间：
2006-12-01
影响因子：
4.2
通讯作者：
Zhang, Qingwen
中科院分区：
文献类型：
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作者：
Li, Jiancheng;Coudron, Thomas A.;Zhang, Qingwen
中红侧沟茧蜂是棉铃虫Helicoverpa armigera（Hubner）和东方粘虫Mythimna = Leucania separata（步行者）幼虫的一种单胞内寄生蜂。不同龄期的选择性和适宜性。separata为M.在实验室条件下，在26 +/-1 ℃、65 +/-5%RH和L14：D10光周期的恒定温度下测定介体。选择系数表明M.介体虫主要寄生在1 ~ 4龄幼虫上，但较好寄生在2 ~ 3龄幼虫上。当以2龄幼虫为寄主，每20头幼虫1头寄生蜂，24 h内寄生率达71%。寄生蜂的羽化和化蛹与寄主的龄期有关，一般发生在1 ~ 4龄。从卵到包皮的平均发育时间。在1 ~ 4龄寄主体内的中介期分别为8.27、8.30、8.30和9.20天。以1龄和2龄为寄主的茧重较3龄和4龄为低。随着寄主年龄的增长，1 ~ 5龄幼虫的死亡率逐渐下降，分别为26%~ 2%。本研究结果表明，2龄和3龄幼虫对棉铃虫的危害是多方面的。separata是大规模生产M.媒介在实验室和最佳主机龄，以有效控制在现场释放的目标。(c)2006年爱思唯尔公司All rights reserved.
Microplitis mediator (Haliday) is a solitary endoparasitoid of larvae of the cotton bollworm, Helicoverpa armigera (Hubner) and the oriental armyworm, Mythimna = Leucania separata (Walker). The preference and suitability of different instars of M. separata for M. mediator were determined under laboratory conditions at a constant temperature of 26 +/- 1 degrees C, 65 +/- 5% RH and L14:D10 photoperiod. The selection coefficient revealed that M. mediator parasitized 1st to 4th instars, but preferred 2nd and 3rd instars. Seventy-one percent of parasitism was achieved within 24 h when the 2nd instars were used as hosts at a density of one parasitoid per 20 Larvae. Parasitoid egression and pupation were dependent on the host instar parasitized and occurred from the 1st through the 4th instar. The mean developmental time from egg to prepupae of M. mediator within 1st to 4th instars of the host was 8.27, 8.30, 8.30 and 9.20 days, respectively. Cocoon weights were lower when 1st and 2nd instars served as hosts rather than 3rd and 4th instars. The percentage of host larva that died before parasitoid egression declined as the age of the host increased, ranging from 26% to 2% for 1st-5th instars, respectively. The results of this study suggest that 2nd and 3rd instars of M. separata would be the best host stages for mass production of M. mediator in the laboratory and the best host instars to target for effective control in field releases. (c) 2006 Elsevier Inc. All rights reserved.